“The Plant Hardiness Zones divide the United States and Canada into 11 areas based on a 10 degree Fahrenheit difference in the average annual minimum temperature. (The United States falls within Zones 2 through 10). For example, the lowest average temperature in Zone 2 is -50 to -40 degrees Fahrenheit, while the minimum average temperature in zone 10 is +30 to +40 degrees Fahrenheit.”(Arbor Day Foundation)

“If your hardiness zone has changed in [the most recent] edition of the USDA Plant Hardiness Zone Map (PHZM), it does not mean you should start pulling plants out of your garden or change what you are growing. What is thriving in your yard will most likely continue to thrive.

Hardiness zones are based on the average annual extreme minimum temperature during a 30-year period in the past, not the lowest temperature that has ever occurred in the past or might occur in the future. Many other environmental factors, in addition to hardiness zones, contribute to the success or failure of plants. Wind, soil type, soil moisture, humidity, pollution, snow, and winter sunshine can greatly affect the survival of plants. The way plants are placed in the landscape, how they are planted, and their size and health might also influence their survival.” (United States Department of Agriculture)

When you’re looking for the best trees or perennials to add to your landscape, do your research and know your zone to ensure the best growth for each plant. If you have questions about which trees or plants grow best in your zone, contact a local certified arborist.

Browning Tree Service is a proud member of Indiana Arborist Association and International Society of Arboriculture, serving the West Lafayette and Lafayette, Indiana area!

Resources:

https://planthardiness.ars.usda.gov/PHZMWeb/About.aspx

https://shop.arborday.org/content.aspx?page=zone-lookup